I encounter railroad workers on my way to school almost everyday. I always think that for a minimally paying job, railroad work requires considerable physical efforts on the part of the workers. Indeed, they have to work under extreme temperatures and stand in exhausting positions throughout the day. But aside from these difficulties, they also have to work with dangerous materials and machines, all together creating a high-risk working environment. In addition to the harsh conditions of the railroad environment, there are genetic risks associated with this line of work.
Railroads are hazardous workplaces and rail vehicles pose hazards even to workers in non-railroad occupations. Casualties result from some of the activities railroad workers are involved with on a daily basis. Among them all, transportation accidents cause the most fatalities. These include railway accidents (railway vehicle crashes, and falls in, on, or from railway vehicles), as well as pedestrian workers being struck by construction or railway vehicles. Other fatalities happen from contact with harmful objects, suicides of employees, homicides and electrocutions.
I found that the research papers were mainly focused on three categories of workers: locomotive drivers, railroad car painters and railroad transit workers. Being exposed to different environments and using different instruments, each type of railroad worker is at risk for different genetic damage.
Locomotive drivers, to start with, are constantly exposed to very loud noises and therefore, are particularly at risk for sensorineural hearing loss, which is caused by damage to the inner ear or the nerve from the ear to the brain. Moreover, they lay open to high magnetic fields, which induce genetic damage specifically in blood lymphocytes. A cytogenetic analysis of cultured (48h) peripheral lymphocytes from 18 locomotive drivers indicated a significant difference in the frequency of cells with chromosomal aberrations in comparison with 7 train dispatchers and a control group of 16 office workers. The locomotive drivers had about 4 times higher frequency of cells with chromosome-type aberrations than the office workers (P < 0.01) and the dispatchers (P < 0.05). Due to the genetic damage targeting blood lymphocytes and the general increase of chromosomal aberrations, locomotive drivers are at risk for morbid cancer and chronic lymphatic leukemia, which is a cancer of the blood and bone marrow. The unfavorable conditions of work also accelerate aging and decrease the adaptation reaction possibilities of the person.
Railroad painters are subject to all the types of chromosomal aberrations due to their intensive exposure to paints and solvents, which contain harmful chemicals. Many solvents cause neuropathy, the dysfunction of one or more peripheral nerves, which typically cause numbness or weakness. Abnormally slow motor and sensory conduction velocities and/or prolonged motor distal latencies were found in some car painters.
The third category of railroad workers, transit workers, are vulnerable to the genotoxic components of the chemicals transported in the trains, which lead to the development of chromosomal aberrations on a baseline level. A survey conducted on 48 railroad workers and 39 referents showed an elevation of chromosomal aberrations among the railroad transit workers. A positive association existed between the exposure duration and the genetic damage level among the exposed subjects. Railroad transit workers specifically face the danger of deletions, variants, and/or mutations in the genetic coding for peripheral hormone-binding proteins, such as myelin. Railroad transit workers also seem to develop Carpal Tunnel syndrome due to these genetic modifications. The symptoms of Carpal Tunnel syndrome consist of numbness and tingling in the hand and arm. It is often the result of a combination of factors that increase pressure on the median nerve and tendons in the carpal tunnel of the hand. Some of the contributing factors to Carpal Tunnel syndrome are repeated use of vibrating tools, work stress, and trauma to the wrist that causes swelling.
Railroad workers need to be cautious and alert to the physical dangers of their workplace. Additionally, they need to consider the genetic risks associated with their work. Locomotive drivers should wear protective ear-wear to prevent damage from the high frequency noise to which they are exposed. Railroad painters should wear face masks to minimize the inhalation of toxic chemicals. Transit workers can reduce the risk of developing Carpal Tunnel syndrome by wearing protective wrist gear and avoiding repetitive hand stress.
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Catalan J., Heilimo I., Falck GC., et al., 2009, Chromosomal aberrations in railroad transit workers: effect of genetic polymorphisms, Environ Mol Mutagen. 304-16.
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